Centering device for lathes.



' H. J. KROMBACH.

CENTERING DEVICE FOR LATHES.

APPLICATION FILED JULY 16,1913.

1,095,581, Patented May 5, 1914.

HARRY JULIUS KROMBACH, OF NEW YORK, N. Y.

cnn'rnnme DEVICE FOR LATHES'.

Specification of Letters Patent.

Patented May-5,1914.

To all whom it may concern:

Be itknown that I, HARRY JULIUS KRoM- men, a citizen of the United States, resid-' ing in the city, county, andgtate of New York, have made a certain new aniiuseful Centering Device for Lathes, of which the" following is a specification.

This invention relates to centering devices for lathes and particularly devices of this nature employed for holding armature bearings while being bored.

The object of the invention is to provide a centering device which is simple in construction, of few parts, economical to manufact-ure, and eifici'ent in operation.

A further object is to provide a centering device which efliciently grips and holds the article to be bored in absolutely true oentered position.

A further object is to provide means in a device of the nature referred to for eliminating or removing the cuttings of the boring tool.

A further object is to provide means for accurately centering thearticles to'be opertried on even where such articles vary in size.

Other objects of the invention Will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as Wlll be more fully hereinafter set forth as shown' in the accompanying drawing, and finally pointed out in the appended claims.

In the drawing :Figure 1 is a view in end elevation of a centering device embodying the principles of my invention. Fig. 2 is a. view partly in side elevation and partly in longitudinal section on the line 2, 2,-Fig. 1, looking in the direction of the arrows.

In the centering device of my invention I employ a metal chuck or head having a solid end portion 3 which is countersunk and threaded in one end thereof, as at 4 for attachment to the revolving spindle of the lathe. The solid portion of the chuck or head is also exteriorly threaded, for a portion of its length, as indicated at 5. Formed integrally with the solid portion of the chuck or head and extending from the opposite end thereof, is a cylindrical shell or tubular portion. 6, within which the article to be bored is received. This shell or tubular portion" is longitudinally slit through the wall thereof at various suitably spaced Application filed July 16, 1913. Serial No. 779,230.

points, as indicated at 7, to form the spring clamping jaw portions 8. At the inner end 1 of the shell or tubular portion 6, and adjacent the junction thereof with the solid part v3 of-the chuck or head the solid or unslitted portion of the spring clamping jaw 8 are provided with openings 9 through t e wall or shell thereof. The exterior surface of the spring clamp jaw portions v8 are beveled,

as indicated at 10. Mounted upon the exteriorly threaded portion 5 of the solid part 3 'of the chuck or 'head is an interiorly threaded sleeve 11 which extends in encompassing relation over the shell or tubuiar portion 6 the inner wall of the end of srid sleeve loeing beveled to'correspond to he bevel 10 of thesp'ring. clamp ]E1WS, as intlicated at 12. The sleeve 11 is interiorly cored out to form a channel 13 upon the innerv surface thereof. The openings 9 .open into this channel.

' The operation of the device is very-simple.

of the spindle or other part of a lathe and the article to be bored, an armature bearing The chuck or head is screwed onto the endfor instance, is inserted in the shell or tubular portion 6 of the device. The sleeve 11 is then turned in any suitable or convenient manner upon the threaded portion of the chuck or head 3, whereby through the engagement and cooperation of the beveled surfaces 10, 12, the spring clamp "jaws are forced into clamping action upon the article contained in the shell or tubular portion and in absolutely uniform true and centered relation. As the boring operation progresses the cuttings from the tool drop through the holes 9 into the recessed channel 13, from I which they are removed after the boring operation is completed, and the article removed. The' removal of the article is effected by simply backing off the sleeve 11,

thereby releasing the clamp action of the spring clamp jaws upon the articlepermitting the latter to be removed. If-desired the sleeve 11. maybe provided with sockets, indicated at 14 in the exterior surface thereof to receive a spanner wrench for turning the same. Y

-In order to accommodate different sizes of armature bearings or other articles re- Fig. 1, which is removably inserted within the bore of the shell or tubular portion 6 'quiring true and accurate turning in the same centering device I propose to employ a reducing sleeve 15, shown in dotted lines in when a bearing or other article of smallsize is to be clamped and centered. This reducing sleeve is provided with longitudinal slits 16 through the wall thereof to correspond with the slits 7 in the tubular portion 6 and for a similar purpose. It is also provided with holes or openings, similar in purpose and arrangement to the holes '9 and arrangedto register with said holes 9. This reducing sleeve enables me to clamp and center smaller sizes of armature bearings or other articles than can be efficiently clamped without it,.and. with the same degree of trueness and accuracy of centering.

Havin now set forth the obje'ctsf and nature 0 my invention and a construction embodying the principles thereof, what 1 claim as new and useful and of my own invention, and desire to secure by Letters Patent is .e

l. A centeringdifie for lathe work, comprising a chuck or head exteriorly threaded.

and having an integral tubular portion forming an extension of one end thereof, said tubular portion having suitabl spaced longitudinal slits through the wall thereof to form spring clamp jaws and also having holes formed through the solid portions of its wall adjacent the junction thereof with the solid portion of the chuck or head, the exterior surface of said tubularportion being beveled or inclined for a portion of its length and a sleeve interiorly, threaded to be received on the threaded portion of said chuck or head, and having an interiorly beveled portion fitted to and cooperating with the exterior beveled surface of the clamp jaws, said sleeve having an interior channel encompassing the holes through. the walls of said tubular portion and with which said holes communicate.

2. A centering device for lathe work com- 1 prising a chuck or head having; an integral.

tubular portion extending from one end thereof, said tubular portion having longitudinal slits through its wall to form spring clamp'jaws, and holes through the solid portion of its wall and having an inclined or beveled exterior surface for a ort-ion only of its length, and asleeve mova ly mounted upon the chuck or head and having a correspondingly beveled orv inclined surface at the end thereof to cooperate with the inclined surface of the tubular portion, said sleeve having an interior annular channel encompassing said holes and a portion of the length of the slits through the wall of the tubular portion.

3. A centering device for lathe work comprising a chuck or head having an integral tubular portion extending from one endthereof, said tubular portion being longitudinally slitted to'form spring clamp jaws and having an inclined or beveled exterior surface for a portion of its len th and having holes or opening through the solid portions thereof, asleeve movably mounted on I said chuck or head and having an internal beveled or inclined surface to cooperate with the external beveled or inclined surface of the tubular portion, and a slitted reducer sleeve adapted to be removably mounted in' the bore of saidtub llar portion and having cooperating holes .or openings through the solid portions thereof, said sleeve having an interior annular channel arranged to encompass said holes or openings.

In testimony whereof I have hereunto set my hand in the presence of the subscribing. witnesses, on this 14th day of July A. 1).,

HARRY JULIUS KROMBACH.

' Witnesses:

G. A. McGRATH, W. A. DARBY. 

